Unusual derivatives from Hypericum scabrum

Abstract Three new compounds ( 1 – 3 ) with unusual skeletons were isolated from the n -hexane extract of air-dried aerial parts Hypericum scabrum . Compound represents first example an esterified polycyclic polyprenylated acylphloroglucinol that features a unique tricyclo-[4.3.1.1 1,4 ]-undecane skeleton. 2 is fairly simple MPAP, but unexpected cycloheptane ring decorated prenyl substituents, and compound has 5,5-spiroketal lactone core. Their structures determined by extensive spectroscopic spectrometric techniques (1D 2D NMR, HRESI-TOFMS). Absolute configurations established ECD calculations, absolute structure was confirmed single crystal determination. Plausible biogenetic pathways also proposed. The in vitro antiprotozoal activity against Trypanosoma brucei rhodesiense Plasmodium falciparum cytotoxicity rat myoblast (L6) cells determined. showed moderate T. P. , IC 50 values 3.07 2.25 μM, respectively.